Http://volcano-pictures.info/ Crater Lake: Oregon Mount Mazama Volcano Mauna Loa Hawaii fissure.
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Transcript of Http://volcano-pictures.info/ Crater Lake: Oregon Mount Mazama Volcano Mauna Loa Hawaii fissure.
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Crater Lake: OregonMount Mazama Volcano
Mauna Loa Hawaii fissure
What is a volcano:A weakened place in the Earths crust where magma erupts as lava.
Magma: Molten rock, gases, and water.Melting from: Heat, pressure, and waterLava: mostly molten rock, the gases and water evaporate at the surface.
Major volcanic zones: 1. Ring of fire because of subduction zones. Island arcs
2. Mid-Ocean Ridges:seafloor spreading,pillow lava’sIceland
Hot Spot Volcano’s: Hawaii, Yellowstone, Congo, 1.Mantle plumes of magma feed these volcano’s from deep in the mantle.
sill
dike
Volcanic neck Extinct volcano
Lava rock
Plutons
Devils Tower is a Pluton
Section 2: Volcanic Eruptions1.Mafic Eruptions: Magnesium Ma and iron Fe so….. MaFic a. Low Silica (sand or quartz) and gas b. Low Viscosity: Very runny lava c. Quiet eruptions
d. Pahoehoe lava “ropy”: very mafic, runny
e. Aa lava: sharp jagged lava.
f. Blocky lava: higher silica and viscosity.
Felsic Eruptions:1.Violent2. High in silica3.Granitic in nature.
Pyroclastic flow
Types of Volcanoes:1.Shield volcano: like a shield laying upside down. Hawaii is a huge shield volcano
Hawaii shield
Composite Volcano alternating layers of lava and ash build the Volcano into its classic shape.
Lava flowsAsh layers
Toba Caldera: Indonesia
The eruption takes place atseveral placesat the same timewithin the volcano.
Cinder cone: Steep side and made of cinders.
Erupting cinder cone in Hawaii